It looks like a family. In fact, they are two completely different families. The structure of ordinary glass is silicate, but the "parents" of plexiglass are acetone, methanol, sulfuric acid and hydrogen cyanide.
Plexiglass is generally much more stubborn than ordinary glass. Although its density is less than half that of ordinary glass, it is not as fragile as glass. Its transparency is very good, crystal clear, and has a good thermoplasticity, it can be heated, it can be arbitrarily molded into glass rods, glass tubes or glass panels, because it has a lovely appearance and personality, so it has a wide range of uses.
Jet aircraft often encounter severe vibration, sudden change of temperature and pressure of airflow when flying at high speed in clouds, which is a severe test for the window glass of aircraft cockpit. And it's plexiglass that can stand the test. If it was a fighter plane, when it was hit by a bullet in pursuit of the enemy, it would not break the whole piece, but only pierce a small hole, so that no similar accidents like glass fragments would happen again.
Ordinary glass is more than 15 centimeters thick, it will become green, and can not see through the glass. The plexiglass is 1 metre thick, and you can see clearly what's opposite. Because of its excellent transmittance and ultraviolet ray penetration, it is often used to manufacture optical instruments.
Another amazing property of plexiglass is that a curved plexiglass rod, with a curvature less than 48 degrees, along which light can be projected like water through a pipe. How interesting it is that light can take a detour! With this stunt, it becomes a treasure in making surgical light-transmitting glass instruments. Therefore, when doctors operate in the operating room, they need not worry about not seeing clearly.
Plexiglass is light, tough, chemically stable, heated and plasticized, so it has a wide range of applications.
If some dyes are properly added to the raw materials of organic glass, red, green and purple can be made according to people's needs. Colorful plexiglass.